The Insulated Gate Bipolar Transistor (IGBT) is an integrated combination of a bipolar transistor and a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and has become commercially successful due to its superior on-state characteristics, reasonable switching speed, and excellent safe-operating area. The typical lateral IGBT has a gate that is located laterally between the anode and cathode. (See, e.g., U.S. Pat. No. 4,963,951, issued Oct. 16, 1990, inventors Adler et al.: U.S. Pat. No. 5,654,561. issued Aug. 5, 1997, inventor Watabe; U.S. Pat. No. 5,869,850, issued Feb. 9, 1999, inventors Endo et al.). U.S. Pat. No. 6,528,849, issued Mar. 4, 2003, inventors Khemka et al., is of interest in disclosing a super junction dual gate lateral DMOSFET device
Super junction Double Diffused Metal Oxide Semiconductor (DMOS) devices are desirable because they overcome the one dimension silicon device limits for high off-state breakdown voltage and low on-state resistance. In a super junction device, depletion regions are formed in the n and p pillars for high device breakdown voltage. The relatively high doping concentration of the n pillars (for an n channel MOSFET) can reduce device on-state resistance. However, because the p pillars occupy a significant percentage of the device drift area, they do not contribute to reducing device resistance in the on-state in MOSFETS. It would be desirable to have the super junction device designed so that the p pillars make a contribution to reduce the on-state device resistance (Ron).
Lateral IGBTs (LIGBTs) are commonly used power devices for Power Integrated Circuit (PIC) applications because of their superior device characteristics. However, device latch-up, which leads to loss of gate control, may occur at high current due to the existence of the parasitic thyristor (n+ cathode/p-body/n-drift/p+ anode) in IGBT architecture. It therefore is desirable to make a virtually latch-up free IGBT.
There is thus a need for a lateral IGBT device that has reduced on-state resistance and the parasitic npn of the device is never turned on in normal operation, and therefore the lateral IGBT device is effectively latch-up free.